PEST w/ Pilot Points - Exporting Interpolated Conductivity Field

[mmamobile]

Hi,

I've completed a PEST simulation using the pilot points approach to adjust K values within a zone in my model. I would like to export the resulting conductivity field, but the grid values are only held in array form as the key values - that is, the negative key values used to translate the zones to PEST are the only information available.

Is there any way to export these data? I'd even be satisfied with converting to a 2D dataset that could be exported and reimported to a different model (tried this....didn't work).

Thanks!

[Todd Wood]

Hi,

I've completed a PEST simulation using the pilot points approach to adjust K values within a zone in my model. I would like to export the resulting conductivity field, but the grid values are only held in array form as the key values - that is, the negative key values used to translate the zones to PEST are the only information available.

Is there any way to export these data? I'd even be satisfied with converting to a 2D dataset that could be exported and reimported to a different model (tried this....didn't work).

Thanks!

mmamobile,

To export the results of a PEST simulation, select MODFLOW | Parameters and select Import Optimal Values... This will create a scatter set with the optimal values calculated by PEST.

These values are being imported from the .par file, so you could also open that file up to view the values.

Regards,

Todd

XMS Technical Support

[Alan Lemon]

Follow the steps suggested by Todd. Then select the HK data set below the MODFLOW->LPF item in the project explorer. Right-click on the data set and select the View values... command. This will give you all of the values of the resulting HK array. You can copy the contents of the spread sheet to do any further processing.

[GMS User]

I followed Alan suggestion, but I have a question.

I check "Tickonov regularization for pilot points" and "Inverse distance power" for interpolation settings.

How can I rebuild the LPF HK distribution obtained from the Pest Array?

My steps:

1 I import optimal values in a Scatter point feature

2 Interpolate to Grid with Inverse distance power

3 Import HK value by LPF, Horizontal Hydraulic Conductivity, 3D Data set -> Grid

4 Run Modflow (forward)

5 Activate the computed head contouring

The computed head contouring is not the same as the one resulting after Pest optimization.

How can I fix it as I need more than one HK distribution in only a GPR file to perform more simulation.

[Alan Lemon]

If you are using version 9.0 or later you can look at the MODFLOW solution and you should see a folder called Parameters. Inside that folder there will be a data set for HK. You can directly copy this into the HK array. Or you can select the HK array underneath MODFLOW in the project explorer and select the Duplicate command from the right click menu.

If you are using an older version of GMS then you will need to go through the steps outlined above. When you do the interpolation make sure that you are using the exact same interpolation options specified for the pilot points. A common error would be to use IDW and not have the nodal function set to "Constant".

[GMS User]

You are right:

>common error would be to use IDW and not have the nodal function set to "Constant".

I fix it.

Thank you.